This invention relates to apparatus for providing physical comfort and safety during human pregnancy, and more particularly relates to a mattress which enables a pregnant woman to lie frontally downwardly on her abdomen throughout the prenatal period with a minimum of discomfort and a maximum of safety. Heretofore, it has generally been thought to be necessary to minimize, during the prenatal period, the amount of time pregnant women rest in such a position, where their distended abdomens are forced against a relatively non-compliant surface, for example that of a conventional mattress. Both the safety of the fetus and the comfort of the woman may be compromised when she is forced to lie in such a position, particularly for extended periods of tme during the latter stages of pregnancy. Accordingly, a need has arisen for a simply constructed, economical mattress upon which an expectant mother can lie in a frontally-downward position for a desired length of time without suffering excessive physical discomfort or causing injury to the fetus.